Indirect Spectrophotometric Determination of Methyldopa using AuNPs-Cr(VI)

Authors

• Anfal A. Mohammed, Iraqi Ministry of Education, Mosul, IraqFollow
• Zeena Z. Al Abdali, Department of Chemistry, College of Education for Pure Science, University of Mosul, Mosul, IraqFollow

Abstract

A simple, sensitive, and rapid spectrophotometric method was suggested for the indirect determination of methyldopa. The method depends on the chemical reaction between citrate-stabilized gold nanoparticles and chromium (III) ions, which form during methyldopa oxidation through potassium dichromate. The process results in nanoparticle aggregation, while the solution transitions from red to blue-grey, and the plasmon band moves from 528 nm to 640 nm. The absorption rate increased linearly within the concentration range of 60-140 ng/ml, while the detection limit reached 27 ng/mL. The proposed method showed excellent accuracy and precision because the mean recovery value reached 100.16%, and the relative standard deviation stayed under 1%. The method produced results that matched the labeled content of methyldopa tablet formulations, which demonstrated its effectiveness for pharmaceutical testing.

Keywords

Aggregation, Chromium (III), Methyldopa, Nanoparticles, Spectrophotometric determination

Subject Area

Chemistry

Article Type

Article

First Page

2003

Last Page

2011

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

How to Cite this Article

Mohammed, Anfal A. and Abdali, Zeena Z. Al (2026) "Indirect Spectrophotometric Determination of Methyldopa using AuNPs-Cr(VI)," Baghdad Science Journal: Vol. 23: Iss. 6, Article 2.
DOI: https://doi.org/10.21123/2411-7986.5317